1. Field of Invention
The present invention relates to a speaker, and more particularly to a terminal connection device connected to a speaker for selectively connecting the voice coils of the speaker between an internal series connection and an internal parallel connection.
2. Description of Related Arts
A conventional speaker, which is adapted for transferring electrical energy to sound energy, comprises a speaker frame having a hollow shaped frame body, a speaker cone held by the speaker frame, a voice coil having a pair of terminals provided at a rear side of the speaker frame to electrically connect to an amplifier. To operate the speaker, a magnet is coaxially disposed in the voice coil to generate magnetic field in a form of magnetic force. Due to the magnetic force, the voice coil is driven to move coaxially, so as to further drive the speaker cone to vibrate the surrounding air coaxially. So, the electrical energy will then transfer to the sound energy.
Accordingly, there are two individual voice coils supported in the speaker frame for a high-end speaker such that each of the voice coils generates different ranges of sound to enhance the sound effect of the speaker. However, such speaker has several drawbacks.
The voice coils must be internally connected in either series connection or parallel connection for different sound quality adjustment. For connecting the voice coils with the amplifier in series connection, the two voice coils must be electrically connected in series circuit by electrically connecting the negative terminal of one of the voice coils to the positive terminal of the other voice coil. For connecting the voice coils with the amplifier in parallel connection, the two voice coils must be electrically connected in parallel circuit by electrically connecting the negative terminal of once of the voice coils to the negative terminal of the other voice coil. Accordingly, the electrical connection of the two voice coils is not very complicated that the user is able to electrically wire the two voice coils by himself. However, it is a hassle for the user to disassemble the speaker to change the electrical connection of the speaker between the series circuit and the parallel circuit so as to adjust the sound quality with respect to the amplifier.
In addition, the practical difficulty of cable wiring becomes apparent. For electrically connecting between the voice coils, electric cables must be used externally connected the terminals of the voice coils so that the user is able to switch between the series connection and the parallel connection of the speaker with respect to the amplifier. In such circumstance, the externally electric cables not only interfere with other components of the speaker but also degrade aesthetic appearance of the speaker.